Comminuting and mixing of substances of all kinds



Nov. 2, 1926. 1,605,025

H. HILDEBRANDT COMMINUTING AND MIXING OF SUBSTANCES OF ALL KINDS FiledJune 1, 1925 6 Sheets-Sheet 1 Fig.4 v

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H. HILDEBRANDT COMMINUTING AND MIXING 0F SUBSTANCES OF ALL KINDS FiledJune 1, 1925 6 Sheet-Sheet 5 Fig.6

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H. HILDEBRANDT COMMINUTING AND MIXING 0F SUBSTANCES OF ALL KINDS FiledJune 1, 1925 6 Sheet-Sheet 4 Nov. 2 1926. 1,605,025

H. HI LDEBRANDT COMMINUTING AND MIXING OF SUBSTANCES OF ALL KINDS FiledJune 1. 1925' 6 Sheets-Sheet 5 HWOFD ?y M Nov. 2, 1926. 1,605,025 H.HILDEBRANDT 'CQMMINUTING AND MIXING 0F SUBSTANCES OF ALL KINDS FiledJune 1, 1925 6 SheetsSheei; 6

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I UNITED STATES PATENT Fr -ca.

HERMANN HILDEBRANDT, 0F HAMBURG, GERMANY.

COMMIN'UTING AND MIXING 0F SUBSTANCES OF ALL KINDS.

Application filed June 1, 1925, Serial No. 34,159, and in Germany May26, 1924.

It has been heretofore proposed to use the centrifugal force of ballsfor the extreme zomminution of substances; but in such process the ballsand the material were raised or carried through the movable grindingpath without, however, accomplishing a maximum degree of grindingaction.

According to the present invention, the grinding action is increased bycausing the balls and the material to positively traverse a path whichis different from the rotational direction of the movable grindingelement. The motion which is achieved thereby gives the comminutingmeans, for instance, balls on the movable grinding surface a maximum ofmovement energy so that the balls can follow the rotat onal velocity ofthe grinding path in practically every case.

The invention consists further in that the comminuting means togetherwith the material to be treated are moved constantly in a closed circuitby centrifugal force, over one or more movable grinding surfaces andover one or more stationary grinding surfaces, whereby; the direction ofmovement of the current of balls and ,material on the movable grindingsurface is different from the directioniof movement of the latter andthe balls are driven over surfaces or guide paths of a closed workchamber.

An apparatus for carrying out this process comprises guide paths formedby the arrangementof steep walled shell-formed,

' movable grinding elements in combination with stat onary grindingelements.

The comminuting means and the material, on passage from one grindingsurface to the other, may be subjected to an impact action, and likewisethe section and number of the movable and stationary grinding paths maybe modified relatively. The arrangement of the movable and the rigid orstationary grinding elements with respect to each other is, .as shownfor example in the accompanying drawings and explained in greater detailin the specification, so formed that guide paths for the current ofballs and material is produced, which can be further supplemented byguide elements for causing an impact or drop action. The walls of theguide paths are preferably equally spaced apart throughout, except forthe in and outlet points for the current of balls and material. Thehalls are received by the under side of the movable grinding member, areset in rotation and rise together with the material up the steep walledmovable grinding element, leaving the latter at the highest point andpassing to the stationary grinding element. From here they again pass tothe lowermost point of the movable grinding element. The stationarygrinding element may be arranged outside or inside the movable element;With the arrange mentof several grinding elements the technical orpractical possibilities of the assemblage of the individual features ofthe present invention are immediately apparent, so that any combinationcomprising the main feature of the invention 'falls within it. Also thechambers which serve for the impact action of the balls at the point'ofpassage from one grinding element to the other may be in any number, andtheir relative positions modified as desired.

Various substances -can be mixed together in the same way.

The apparatus is illustrated in the accompany ng drawings in which:

Figure 1 is a vertical sectional view of one form of the invention.

Fig. 2 is a similar view of a modification of a detail of the structureshown in Fig. 1..

Fig. 3 is a top plan view of the slotted plate shown in Fig. 2.

Fig. 4 is a vertical sectional view of a modified form of machine.

Fig. 5 is a detail sectional view taken on line A-B of Fig. 4.

Fig. 6 is a fragmentary vertical sectional view of another modification.

Fig. 7 is a similar View of another form of invention. v

Fig. 8 is a vertical sectional view of another embodiment of invention.

F g. 9 is a sectional view of a portion of the machine shown in Fig. 8taken on the line CD of that figure.

Figs. 10 and 11 are vertical sectional views of other forms of theinvention.

In the devices illustrated in Figures 1 to 6 (Sheets 1 to 3) the ballsand the material for example are contained in circulating gu ding andpressure chambers formed for example by one or more deep .rotary shells,an outer stationary grinding track and an inner stationar guidingbody'suspended in the rotary shell.

By the rotation of the shell the layers of balls located in the guidingand pressure chamber, and the material between them are carried round bythe shell by reason of gravitational and centrifugal pressure frictionand moved at a highperipheral speed and tend to pass along the steepshell wall.

It is however not possible for them to do this until their centrifugalforce in the guiding and pressure chamber has reached such avalue'thatit can overcome the frictional pressure and the weight of the layers ofballs located above the rotating shell on the grinding track and in thegrinding chamber between the grinding track and the guide body.. a

In this manner the balls are driven over,

the grinding track whereby the balls comminute by centrifugal force thematerial which moves with them, and in accordance with the shape of'theuper grinding chamber and the stationary guiding bodies are conductedaway from the grinding track inwardly towards the middle and downwardlyupon the rotating shell, whereby they are projected on the upper wall ofthe stationary guiding body by the pressure of the balls following onthe rotating shell in the guide and pressure chamber or by the energy ofrotation of the balls rotating on the grinding track, or afterdestroying the centrifugal energy of the balls rotating on thestationary grinding track fall on the wall of the guide body, furthercomminuting the material which moves therewith and after destroying theenergy of movement pass from the .upper wall of the guide body throughopenings in the stationary guide body to the middle of the rotary shelland here again comminute the material by impact action.

When reaching the rotating shell theballs, with the material betweenthem, have centrifugal force again imparted thereto and the la ers ofballs close up at the bottom and thus effect by this continuousadditional increase in pressure in the guide and pressure chamber, acontinuous pressing out of the balls and the material from the uppergrinding track and a continuous circulation in the mill.

I The material is continuously between the balls and partakes of thecontinuous movements thereof whereby the material is mainly comminutedby impact and friction action of the balls on the grinding track. on

the guide body, and on the bottom of theshell.

ure 7 (Sheet 3) the balls and the material, in a similar manner asdescribed in connection with the devices in Figures 1 to 6. are drivenupwardly continuously from the roistationary, may form a guiding and Bymeans of the device illustrated in Fig- I tating shell and also have agrinding movement imparted thereto by reason, of the guide members orguide ribs provided at which either with a shell, open at the bottom-andtop, and inserted therein and rotating therewith or suspended thereinand pressure chamber, by reason of the high bearing pressure against thesteep shell wall resulting from centrifugal force and guided upwardlyand driven over astationary grinding track, from which the balls and thematerial ,by means of the energy of rotation are projected by projectingribs on the grinding track downwardly directly to a suitable point ofthe rotating shell or on,

the upper wall of the suspended stationary guiding body and from hereare passedthrough a central opening to the middle of the rotating shelland thus mainly by the impact action when the balls strike the wall ofthe rotating shell or the stationary guiding bodies-together with thediverting pressure comminute the material which moves therewith.

In the devices illustrated in Figures 10 and 11 on Sheets 5 and 6, theballs and the material have imparted thereto a high peripheral speed andthe absolute speed of the rotating shell by means of rotary shells openat the bottom and at the top and gradu ally enlarged towards the topandarranged around the shaft and secured thereto, .by

reason of the gravitational friction and the friction due to centrifugalpressure, and by reason of the centrifugal force thus obtained arecontinuously guided from the bottom to the top and projected with theprojecting force suitable for every kind of material on the stationarygrinding track which surrounds the rotating shell at predetermineddistances, from where the balls and the material by reasonof the energyof rotation remaining on the grinding track or .by gravity are conductedor fall into the .stationary casing shell surrounding the rotating shellat predetermined intervals, and,

from the casing shell bottom are pressed and guided by means of thecolumn of balls above them upwardly on the guide body arranged centrallyin the casing shell bottom and through the lower inlctop'enings of therotating shells to the inner surfaces thereof or to the guirliugchambers thereof,

and from here they are driven upwardly and projected on to the grindingtrack in a continuous stream by reason of the friction peripheral speedand a high projecting force ing tracc on which the material is broken upor comminuted, and at the same tlme to resulting set the balls and thematerial into a contin ing energy of a flowing medium through 7 upperopenings and the wet material is periodicaly emptied through loweropenings and the supply of all the material is effected through upperopenings.

' and upwardly,

In the device according to Figure 1, Sheet 1, there is secured to avertical shaft 1 a deep rotating shell "2, freely supported at the topwhich is closed at the bottom and open at the top into which a number ofsimilar shells 2 rotating therewith and open at the topand bottom can beinserted in such a manner that between them are formed free guiding andpressure chambers, preferably all arranged at the same distance apart,for

guiding one or more layers of balls and materials The inserted rotaryshells open at the top and bottom are preferably secured to the outershell by means of distance pieces and securing elements. 7

These rotary shells 2,,a stationary grinding track 3, and a stationarysuspended guide body 4, form annular chambers 5 and 6 in which arecontained the grinding bodies 7 and the material. The-guide body 4 is ofsuch a shape and so arranged that its lower wall is similar to theadjacent wall 7, of the rotary shell 2 and thus is every where at thesame distance from the rotating shell and this distance is such that inthe guiding and pressure chambers thus formed, one or more layers ofballs and the material can have a high peripheral speed and centrifugalforce imparted thereto and be driven upwardly by the gravitational andcentrifugal pressure on the rotating shell.

By rotating the deep shells '2 the balls and the material in the guidingand pres sure chambers 5' tend to move outwardly but can;only passupwardly into the grinding chamber 6 when the upwardly acting pressureof the bal s rotating on the rotating shell and to which centrifugalforce has been imparted, has become therefrom when striking the grind-So great that it can overcome the centrifugal energy. the weight and thefriction of the whole column of balls rotating more centrifugal force isimparted, and thus also the comminuting action can be increased.

By reason of the centrifugal force the balls exert a very high pressureoutwardly on the shells and grinding track and upon one another by whichthe material, which is between the balls and continually movestherewith, is energetically comminuted.

Towards the topthe speed of rotation of the balls in their almosthorizontal track which passes upwardlyis reduced by reason of thegrinding operation which is carried out on the stationary grindingtrack.

The balls and the material cannot return in the narrow chambers 5 and6but are gradually driven upwards by the pressure of the succeeding ballsand material in the grinding and pressure chamber 5 until finally, byreason of the stopping of the guide body 4 in the upper part of thegrinding chamber 6, leave the inner side of their guide and vare thusforced or projected or fall towards the middle on the upper wall of theguiding body 4, whereby they further comminute the material on the wallof the stationary suspended guide body when beating open this by impactand on further rotation by friction.

The balls and material finally fall from the upper wall of the guidebody through a central opening 8 in the guide body on carried therewithtowards the interior and to the middle of the shell as they would bealways forced outwardly by centrifugal force and towards the largestdiameter and it is only by the above described method of guiding thatthey can be returned towards the interior and towards the bottom to themiddle of the rotating shell.

Thearrangemen-t of guide ribs or guide bodies on the inner surface ofthe grinding track also enables the balls and the material to be thrownor returned to the middle of the shell and to the bottom by reason of.the energy of rotation. which they still rev tain from the grindingtrack, or when striking on the raised portions of the grinding track arecaused by the elasticity of the balls to jump from the grinding trackand fall towardsthe middle of the rotating shell.

The wedge-shaped annular slot 9 formed between the rotating shell 2 andthe stationary grinding track 3 is closed by a wedge ring 1O,vadjustable from the outside, in such a manner that the centrifugal forceacting therein towards the guiding chamber will force any material whichhas entered the slot back into the guiding chamber.

For supporting this action there is also provided a blade ring 11,secured to the rotating shell 2, of which the blades produce an airpressure in the chamber 12 so that any material which may have enteredthe slot, will be thrown back by the air pres-- sure into the grindingchamber.

The guiding body 4 is secured to the easing cover centrally by means ofribs 13 and bolts 14, whereby the cooling and heating liquids areconducted to the hollow guide body through passages in the bolts 14 andribs 13. In the casing cover is'provided a discharge opening 16 and anopening. 17 through which the most finely ground dry material can bewithdrawn from the guiding chamber-through a flow medium.

The discharge of the fine material is ef fected, in so far as dustyparticles are not withdrawn from the bottom, through a discharge openingarranged centrally at the lowest part of the rotating shell 2, which isopened and closed by an axially movable discharge plunger 18. Fordischarge the plunger is lowered by the spindle 19 by means of thetoothed wheels 20 whereby the material passes through the apertureformed between the plunger 18 and the acking plate 21 into the dischargechamtier 23 and from here is projected through the holes 24 into thewithdrawal chamber 25. The plunger 18' can also be pressed against thepacking plate by spring action.

The discharge slot 22 is much smaller than the balls so that thesecontinue to rotate without interruption. I

The packing plate 21 may also be provided with longitudinal slots 22 asshown in Figures 2 and 3, which are closed by suitably raised portionson the discharge plunger.

In the device according to Figures 4 and 5. Sheet 2. the uniformdistance of the stationarysuspended guide body 4 from the rotating shell2 is. so large that a number of rows of balls and layers of balls have.room side by side whereby the guiding and pressure chamber 5 becomesgreater and the grinding action on the grinding track and also betweenthe separate balls becomes more intense. The same result will beobtained by enlarging the distance between the shells open at the bottomand at the top and fitted within the lower rotating shell with whichthey rotate.

In order to impart to the balls in the guiding chamber a more intensegrinding action and also to return them more rapidly to the centre ofthe shell, the stationary grinding track 3 and the stationary guidingbody 4, the latter, however, only on the upper wall, may be providedwith guide ribs 26 which are arranged transversely or at an angle to thedirection of the movement of the balls.

"In the device according to Fig. 6, Sheet 3, the slot 9 extendsupwardly. In this manner particles of material which pass into the slot9 are conducted back to the grinding chamber also by gravity inaddition'to the centrifugal force and the compressed air which isproduced by means of the blades 11 secured to the shell. By reason ofthe upwardly drawn shape of the grinding chamber '6, not only thegrinding surfaces, but also the tall in height over the. balls and thusthe impact action for comminuting the materialon the shell bottom areincreased.

The cooling or heating of the rotatin shell is effected by a liquidwhich is applied to the outer rotating shell wall by a nozzle ring 27and by 'ablade ring secured to the rotating shell, and rises upwardlythereof by reason of centrifugal force, whereby the liquid is preventedfrom being thrown off too early by the hood 28. At the largest .diameterthe liquid is thrown oil and conducted away at the opening 29.

The upper outflow opening 17 for the dry mate-rial and the inlet opening16 for all the material are in this case arranged cen; trally.

In the device according to Fig. '7, Sheet 3, the stationary guiding bodyis provided on its side turned towards the rotating shell with guidebars or guide ribs extending up to the shell which may be arrangedvertically or at an angle in relation to the path of the balls, wherebythe balls have a rolling and grinding movement imparted there to whenmoving up the rotating shell.

In the devices according to Figures 8 and .9, Sheet 4, projecting ribs31 are provided on the stationary grinding track 3, which are of such acurvature that the balls and the material can be projected substantiallyhorizontally from the upwardly directed track in any suitable directionby reason oi the energy of rotation. The projecting ribs 31 are eitherformed integral with the. grinding track 3 or insertedtherein as aseparate part whereby they may be formed hollow and arranged so as to becooled or heated.

The devices according to Figures 10 and 11, Sheets 5 and 6, only differfrom the previous devices therein that'in these devices the grindingoperation is mainly -ef fected by impact action and wherein the ballsand the material after beating upon the grinding, track fall downwardlyoutmaterial. By gravitational and centrifugal friction they aredriven-by the rotating shell 2, have a high peripheral speed andcentrifugal forceimparted thereto by this and are driven upwardlyp-Atthe upper edge they pass outwardly fronithe shell and by impact actionstrikeuponi the grinding track 3, arranged outside,fwhereby the maingrinding operation is effected. Whilst moving spirally or fallingandcarrying out a further grinding operationthe balls and the material byreason of their gravity move downwardly and collect. in the-bottom ofthe casing shell 33'. They gradually heap up and thus bytheir we'ightforce .OlltL the balls and the material lying in 'the middle of thecasing shell around the g'uiding body combined.-v with a the dischargeplunger 34 and projectinginto thej grind v ing chamber or into the"loweropenin'g of the rotating shell, sothat they; again come withinreach of'the inner surfaces of the rotating shell 2 and are caused torotate with the rotating shell by friction whereby the operation isrecommenced. In these deat this point is not possible;

vices the slot 9 1ies in thedirec tion of the ball track so thatan'outflow of the material The rotating shell 2-is closed towards thecollecting chamber in the casing shell 35 so as to prevent anydeleterious friction with the balls and material, by a stationaryprotecting shell 36.

The protecting shell 36 is suspended and secured in the larger casingshell which surrounds the protecting shell at suitable dis tancestherefrom, by means of distance pieces thus forming the guiding andpressure chamber for guiding the balls and material downwardly. Theslots 37 and 38' formed betweenthe rotating shell 2 and the stationaryprotecting shell 36 are located in the operating chamber and thereforedo not lead to any losses. Any material which may enter the chamber 39formed by the rotating shell 2 and the stationary protecting shell 36 isagain 'terials,

moved upwardly into the guiding chamber by the fan blades 40. With asufiiciently large annular space between the stationary casing shell 33and the rotary shell 2 the stationary protecting shell 36 may also beomitted.

The raising of the securing elements for l the rotary shells to'the hubof the shaft enother and secured upon a common shaftfor guiding one ormore layers of balls and material upwardly. The discharge of the fluidmaterial is then effected downwardly through a discharge openingarranged centrally or laterally at the bottom at thedeepest part of thecasing shell and closed by means of axially movable discharge plunger34. The packing surfaces of the discharge opening in the casing shell 331and of the discharge plunger 34: are conica The Withdrawal of the'drydust-like material is effected through the hollow shaft or through thehollow hub upwardly.

The charging is effected through a pipe 41 suspended centrally in thetop of the hollow shaft.

All the stationary and rotary shells and the grinding tracks accordingto the devices in Figs. 1 to 11 can be cooled or heated. All the partsexposed to wear can be fitted with. armouring which can be rapidlyreplaced. 7

As grinding bodies it is possible to use balls or otherwise shapedbodies of the same or different sizes and of the same or differentmaterial so that when using balls of differthus assist in producingrelative friction between the balls and this friction, when usinggrindin or mixing bodies of different ma- "by reason of the differentco-efiicients of friction between, for example, spherical grinding andmixing bodies, is increased and thus the comminution or mixing of thematerial is supported.

' The above described devices can also be used for mixing varioussubstances with or without the addition of pressure, vacuum, temperatureor electric discharges.

The comminuting process for comminuting up to colloidal fineness can beeffected with the assistance of protecting colloids and the mixingprocess with the assistance of I claim as new and desire to. secure byin which 1;

provided with ribs for directing the grinding elements and the materialinto the guid- Letters Patent is 1. An apparatus for comminuting andmixing materials up toa colloidaldegree of fineness comprising anenclosed operating chamber, at least one stationary grinding track andat least one guide passage arranged in the chamber, comminuting meansarranged in the chamber, and at least one impelling means for movingsaid comminuting means together with material to be treated constantlyin a continuous stream, by centrifugal action over the stationarygrinding track and through said guide pass sages. v v

2. An apparatus for comminuting material to a colloidal degree offineness and admixing the same comprising a rotatable substantiallyparabolic grinding surface, a

complementary shaped stationary grindingsurface spaced from the firstmentioned grinding surface to provide a guiding path .extending upwardlyand outwardly from the axis of the rotatable vsurface, an annularstationary grinding surface arranged at the upper end of said path, andguiding means arran ed to direct grindin elements and the materlalunder-going grinding fromvthe stationary annular surface to the lowerportion of the first mentioned grinding surface.

- 3. An apparatus as claimed in claim 2 in which the guiding meansdirects the grinding elements and material first in a horizontaldirection and then downwardly.

4. An apparatus as claimed in claim 2 in which the guiding meansincludes a substantially horizontal surface provided with impact andguide ribs extendin into close proximity to said annular gui ingsurface.

5. An apparatus-as claimed in claim 2 e annular guiding surface is mgmeans.

6. An ap aratus as' claimed in claim 2 in which the rst mentionedgrinding surface terminates at its lower portion in a substantiallyhorizontal unbroken surface. s

7. An apparatus as claimed in claim 2 in which the first mentionedgrinding surface is formed on a rotatable pan, and a substantiallyparabolic hollow member mounted on extending into the space formed bysaid sub-' stantially parabolic grinding surfaces.

9. An apparatus as claimed in claim 2 in which the substantiallyparabolic rotatable grindin .surface is formed in a rotatable pan, sa1pan having an opening at its lower end, and a plunger normally closingsaid opening.

10. An apparatus as claimedin claim 2 v in which the stationarysubstantially .parabolic surface is formed on a hollow sus pended memberand means for introducing a temperature changing medium into and out ofsaid hollow member.

11. An apparatus as claimed in claim 2 in which the rotatablesubstantially parabolic grinding surface terminates ad'acent to theannular grindingsurface, sai surfaces being separated by an annularspace wedge shaped vertically.

12. An apparatus as claimed in claim 2 in which a wedge-shaped openingis provided between the rotatable grinding surface and the annulargrinding surface, and a rotatable fan for preventing material fromdischarging through said opening.

' movement over the movable surface and then to the movable track.

16. An apparatus as claimed in claim 1 including at least one impactsurface, and another passageway for feeding thecomminuting means andmaterial undergoin treatment from said surface.

17. A device for comminuting and mixing materials up to a degree ofcolloidal fine ness includlng a closed working chamber formed by astationary grinding track and an annular movable grinding track, and

comminuting means movable over said tracks b centrifugal force exerted.by the movable track.

18. A device as claimed in claim 17 in which the movable :grindingtrackis provided with anannular inclined surface arranged adjacent to asimilarsurface on the chamber, said surfaces being directly oppoguidepasagesto the impact 'site one another and being inclined in thedirection in which the comminuting means moves, so as toprevent finematerial from passing out of the chamber between said surfaces.

19. A device as claimed in claim 17 in which the movable track and astationary. Wall of the chamber are provided with adjacent inclinedannular surfaces forming an 10 annular space leading into the chamber,

said surfaces being arranged in the direction of flow of the comminutingmeans so as to prevent material from the chamber discharging throughsaid opening, and a pressure chamber communicating with said opening forfeeding a gaseous mediuin into the closed chamber.

In testimony whereof I afiix my signature.

HERMANN HILDEBRANDT.

